I don't agree with the phrase "People fear what they do not understand". I agree with the phrase "Fear is the beginning of wisdom". Fearless people are the biggest troublemakers and have the shortest life expectancies. You know why? Because they're stupid, that's why. Our jail cells, hospital beds, and cemeteries are filled with people who weren't afraid of things they should have been afraid of.
Kids under five years old don't understand that sticking a paperclip into an electrical outlet could kill them, but they're not afraid to do it. They also don't understand that drinking drain cleaner could kill them, but they're not afraid to do that either.